The present invention relates to a variable lift engine valve gear for an internal combustion engine.
Japanese Patent Application First (unexamined) Publications Nos. 63-57806 and 63-167016 disclose a valve actuating apparatus. The known valve actuating apparatus comprises a mechanism to releasably interconnect the adjacent two cam operated rocker arms. The rocker arms are formed with mating bores receiving a plunger. The plunger is movable between a first position in which the plunger is disposed in one of the mating bores and a second position in which the plunger is inserted into the other plunger and thus disposed in both of the mating bores. When the plunger is in the first position, the two rocker arms move separately, while when the plunger is in the second position, they move as a unit.
This mechanism using the plunger and mating bores, however, requires high degree of precision in forming the mating bores and the plunger.
It would be desirable to be able to provide a valve gear which does not use a plunger or bores which demand high degree of precision to form.
An object of the present invention is to propose an improved installation of variable lift valve gear in an internal combustion engine such that the number of solenoids required in controlling the shift in state of the valve gear is minimized.